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Proceedings of Indiana Academy of Science 



explain, for example, the fact that the mortality from cancer is relatively 

 low in all of the southwestern part of the state. Most of the black 

 counties, except in the south, contain considerable industrial populations 

 (see figure 12). Some think that the exciting lives and rich diets in 

 our busy cities tend to increase cancer. The high mortality in some of 

 the southern counties may be due to the fact that most of the young 

 people have left, leaving the older folks, the danger from cancer in- 

 creasing with age. Figure 10, showing the change in population be- 

 tween 1890 and 1920, is interesting in this connection. Comparisons 

 of figures 9 and 10 show, for example, that several of the counties which 

 have increased most rapidly in population have a low cancer rate, 



Fig. 11. Average death rate per 1,000 

 persons in the five-year period 1917-21, ac- 

 cording to reports of the State Board of 

 Health. 



Fig. 12. Density of i)opulation in 1920, by 

 counties. 



presumably partly because few of their people have reached the age 

 when cancer is especially prevalent. The low death rate from cancer 

 in the coal mining counties of the southwestern part of the state may 

 be partly explained by the demand there for workers in their prime. 

 Other white counties in the southern part of the state may have a 

 low reported death rate from cancer because the cause of the death of 

 many of the pooi'er residents of the rougher counties may not be accu- 

 rately diagnosed. 



General Death Rate. — Figure 11 shows the average death rate from 

 all causes for the five years, 1917-1921. It shows the least contrast 

 of this series of death rate maps. The black counties have an average 



